Bridge construction



(No Model.)

0 H PLATT BRIDGE ODNSTRUGTION.

Patented June 18,1895."-

NOJ 541,213.

6' INVENTOR- Ufiazzles H PZaZZ,

I WITNESSES.

UNITED STATES PATENT OFF C CHARLES II. PLATT, OF LONG ISLAND CITY, NEW YORK.

BRIDGE CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 541,213, dated June 18, 1895.

Application filed March 15, 1895.

To all whom it may concern.-

' of Long Island City, in the county of Queens and State of New York, have invented certain new and useful Improvements in Bridge Construction, of which the following is a specification.

My invention relates to the construction of bridges and arches, and more particularly to that form of bridge construction wherein it is desired to secure a continuous water-tight roof or ceiling for the interior of the arch. This has been accomplished in several Ways, but more frequently by the use of cement or concrete, which on hardening'presents a uniform and continuous surface. Thus in the United States Letters Patent to J. Melan, No. 505,054, dated September 12, 1893, a method of arch construction is set forth which contemplates the employment of curved ribs, designed to bear the weight of the structure and the load, the intervening spaces between said ribs being filled in by rammed concrete. To effect this filling in between the ribs it is necessary to employ a temporary structure or centering, which is used while the concrete is being laid and until it has hardened, the centering being then removed.

To avoid the employment of such temporary structure or centering, and at the same time to secure an arch with a continuous and water-tight ceiling, and one which combines ease and cheapness of construction with great strength and lightness, I propose to employ a continuous series of curved artificial stone plates in connection with curved I-beams, as more fully set forth hereinafter in the specification and pointed out in the claims.

To this end then my invention consists in the combination of curved I-beams and curved artificial stone plates, in the peculiar construction of the curved stone plates, and in certain other features of construction designed to secure strength and rigidity and to permit of necessary yielding and contraction and expansion.

While I am aware that in the construction of buildings, slabs and plates have been employed to span the spaces between the beams, such construction could not be availed of for Serial No. 541,385- (No model.)

bridges, as the beams, slabs and cement fillin g unite in one solid and rigid mass, Without the elasticity and capacity for yielding necessary for the great loads and sudden impact to which bridge structures are subjected, and to permit the expansion and contraction of metal due to the greater extremes of temperature. Such construction, if employed in bridges, would be in constant danger of fracture or cracking, either in the arch itself, in

the slabs, or in the concrete filling. To secure a light, rigid, firm structure, and at the same time to permit of the necessary yielding and elasticity is the object of my present invention.

In the accompanying drawings, which form a part of this specification, Figure 1 is a view of the intrados of an arch constructed according to my invention. Fig. 2 is a sectional view of the crown of the arch, taken transversely to the I-beams; and Fig. 3 isa sectional view taken parallel to the I-beains on the line 3 3 in Fig. 2.

In the drawings, the curved I-beams 2 are supported on the abutments or other suitable supports 3, and on these curved I-beams 2 and between them are placed in continuous series and edge to edge the curved artificial stone plates 1. It will be seen that the'curve of the stone plates 1 is transverse to that of the I- beams 2, and that this double arch construction combines great strength with lightness. Further, the placing of the plates edge to edge gives a continuous and unbroken ceiling, possessing all the advantages and appearance of the solid concrete, and avoiding the expense and delay of the other construction and entirely dispensing with temporary centering.

The curved stone plates or slabs 1 are constructed of concrete, alone or in combination with other suitable materials, andwhen molded into the desired form, are artificially hardened in anyproper manner. Although the exact dimensions and radius of curvature of the slabs or plates are not essential to the practice of my invention and may be varied at will, I prefer to construct them of a length sufficient to span the distance between the I-beams, about two feet in breadth, and of a thickness of not less than two inches. These plates or slabs when carefully constructed of the proper curvconsisting only of the bituminous mastic.

ature and thickness, and artificially hardened, I have found to combine the maximum of strength with the minimum of weight and to be both sound and durable. The ends of the plates may be molded either to fit directly on the flange of the I-beams as shown at 4: at the left of Fig. 2, or to fit into the supplementary skewback 5, as shown at the right of Fig 2. As before stated the plates 1 are placed in series, edge to edge, to secure a practically watertight and continuous structure, but to further insure this, I prefer to construct the plates 1 having one edge 6 square or rectangular (see Fig. 3), and the other edge with an acute angle or bevel 7. These plates when laid present from beneath a continuousand unbroken surface, bnt on top between each pair of plates is left an angular space or recess. This recess is designed to receive the edge of the correspondingly bevel shaped tie-rod 8 (see Figs. 2 and 3), without breaking the continuity of the arch ceiling, or may be filled with an elastic or damp course 9 of woven jute, hemp, asbestos or other fiber, or rubber fabric, saturated with some bituminousrmastic, or I may employ a course In practice I employ the tie-rods 8 at each third or fourth plate, and use theelastic or damp course 9 in the other recesses, in either case filling in with the bituminous mastic. It will be seen that this constructionand arrangement secures not only a perfectly water and air-tight joint, but because of the yielding character of the filling permits sufficient play and elasticity of the structure to obviate largelyanyliability to fracture or. cracking of the plates due to jar or heavy loads.

To still further permit of play in the structure and to provide elasticity, for contraction and expansion due to change of temperature, I either partly or entirely surround the I- beams 2, (and skewbacks 5 when employed) with an elastic or damp course 10, (see Fig. 2) similar to that already described always thoroughly saturating the joint with the bi tuminous mastic. It will be apparent that without affecting the rigidity of the structure, this arrangement gives a series of thoroughly air and water-tight joints, and affords-a cere tain amount of play and elasticity.

Other features shown in the drawings but which are not essential to the practice ofmy invention are the cement sealing l1,,which may or may not be employed, and the filling 12 and paving 14, which may be of any suitable character.

I have described my invention broadly and indicated a mode in which it maybe specifically applied. Obviously, many changes in and elastic or damp courses between the con tiguous edges of said plates substantially as described.

2. The combination of suitable abutment-s or supports, Ibeams supported thereby, and

curved artificial stone plates carried on said i i I-beams, with elastic or-dampcoursespm'fly or entirely surrounding; saidrLbeams; substantially as described.

3. The combination of suitableabutmenta or supports, I-beams supportedfthereby, skewbackson said I-beams, and curvedmrtifioial stone plates on said skew.backs,,-\vith,: elastic or damp courses partly or entirely surroumling said I-beams, and ske\vbacks,-jsubatautially asdescribed.

4. In combination, suitable abutments or supports, I-beams supported therebym gserieo of plates I supportedv 1 on. said Lbeamsi said plates being formed-to leave an angular joint between contiguous plates, ;and elastic'mr dam p courses laid in saidangular joint s,.sub-

stantially asdescribed.

5. In combination, suitable-abutmentsror su pports, I-beams, carried thereby,aseries,o[

artificial stone plates having one edge square and one edge beveled, and. elastic orxdamp courses laid between these. edges,lsu.bstautially asdescribed.

6. In combination, suitable .abutmentsor supports, I-beams carried thereby; a seriesof artificial stone plates, having one edge square and one edge beveled, and :tie-rodswhaving a beveled edge .to fit between the contiguous edges of the stone plates, substantially-asidescribed. I

7. In combination,- suitable .abutmentsvor supports, I-beams carried thereby, a series of plates supported on said-.Lbeams, saidplates being formed to leaveauangular joint:be-

tween contiguous plates,;and tie-rods having a beveledor angular edge tofit said .angular joints, substantially as described.

Signed at NewYork, in the county .of-New York and State of New York, this 13thzday of March, A. D. 1895.

CHARLES. H. PLATT. WVitnesses:

ROBERT F. ROGERS, JOHN A. WESTBROOK.

loo :05

IIOW. 

